package com.zkc.zblog.md5;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;


public class MD5Util {
    private MD5Util() {
    }


    static MessageDigest getDigest() {
        try {
            return MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
    }


    public static byte[] md5(byte[] data) {
        return getDigest().digest(data);
    }


    public static byte[] md5(String data) {
        return md5(data.getBytes());
    }


    public static String md5Hex(byte[] data) {
        return HexUtil.toHexString(md5(data));
    }


    public static String md5Hex(String data) {
        return HexUtil.toHexString(md5(data));
    }

    public static String getMD5Str(String str) {
        MessageDigest messageDigest = null;

        try {
            messageDigest = MessageDigest.getInstance("MD5");

            messageDigest.reset();

            messageDigest.update(str.getBytes("UTF-8"));
        } catch (NoSuchAlgorithmException e) {
            System.out.println("NoSuchAlgorithmException caught!");
            System.exit(-1);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        byte[] byteArray = messageDigest.digest();

        StringBuffer md5StrBuff = new StringBuffer();

        for (int i = 0; i < byteArray.length; i++) {
            if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)
                md5StrBuff.append("0").append(
                        Integer.toHexString(0xFF & byteArray[i]));
            else
                md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));
        }

        return md5StrBuff.toString();
    }

    public static void main(String[] args) {
        System.out.println("MD5:" + MD5Util.md5Hex("73nZ8mvmILeIa1oyC8Zv2015-04-23 10:42:20zonghou总后军区物资fb8704ed02ee4ec23288fc6893e1d270access_token73nZ8mvmILeIa1oyC8Zv"));
        System.out.println("MD5:" + MD5Util.getMD5Str("18811098648"));
    }

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));
            else
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetname)));
        } catch (Exception exception) {
        }
        return resultString;
    }

    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};
}
